1. Field of the Invention
The present invention relates to a field emission device (FED), and more particularly, to a method of manufacturing an FED in which the number of photomask patterning processes is small and an emitter hole forming process can be precisely controlled to improve the manufacturing yield of the FED.
2. Description of the Related Art
A field emission device (FED) is a color image display that realizes a color image by applying an electric field to an emitter formed on an electrode to emit an electron beam from the emitter onto a phosphor material.
The core technology of a FED lies in the manufacturing techniques of an emitter tip from which electrons are emitted, and in the stability of the emitter tip. In a FED, a silicon tip or a molybdenum tip has been used as an emitter tip, but since silicon and molybdenum tips have short lifetimes and low stability, the electron emission efficiency thereof is low. Thus, carbon nanotubes that have excellent electron emission efficiency have been commonly used as emitters for FEDs. Due to their wide viewing angles, high resolution, low power consumption, and excellent temperature stability, FEDs can be used in various applications such as car navigation devices and view finders of electronic imaging devices. FEDs particularly have advantages for alternative displays of personal data assistants (PDAs), medical devices, high definition televisions (HDTVs), etc.
A FED includes a plurality of emitter arrays, and each emitter can be installed in an emitter hole. Accordingly, a FED manufacturing process necessarily includes an emitter hole patterning process to install the emitters in the holes, and a very precise photolithography process is required to make patterns of fine emitter holes. In detail, a FED manufacturing process requires a photolithography process having at least two steps. However, when emitter holes are manufactured in a plurality of photolithography processes, the FED manufacturing process becomes complicated and the manufacturing cost increases. Furthermore, a fine emitter hole with a diameter of 15 μm or less is difficult to realize with a large number of photolithography processes, and thus the manufacturing yield of FEDs can be reduced.